This is solved by intercepting FetchXML. Values for custom attributes not passed from the UI. No change for plugin code as it was debeloped to support FetchExpressions. Source code as below.
function SetReleatedEmailSubgrid(executionContext) {
var isUnified = isUCI();
if (isUnified) {
var formContext = executionContext.getFormContext();
var objSubGrid = formContext.getControl("RelatedEmails");
var entityId = Xrm.Page.data.entity.getId();
if (objSubGrid == null) {
setTimeout(SetReleatedEmailSubgrid(executionContext), 2000);
return;
}
//cc_relatedemailsid is a custom field
var FetchXml = "<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false' returntotalrecordcount='true' page='1' count='4' no-lock='false' >" +
"<entity name='email' >" +
"<attribute name='statecode' />" +
"<attribute name='subject' />" +
"<attribute name='to' />" +
"<attribute name='from' />" +
"<attribute name='statuscode' />" +
"<attribute name='prioritycode' />" +
"<attribute name='createdon' />" +
"<order attribute='createdon' descending='true' />" +
"<filter type='and' >" +
"<condition attribute='cc_relatedemailsid' operator='eq' value='" + entityId + "' />" +
"</filter>" +
"<attribute name='activityid' />" +
"<link-entity name='email' from='activityid' to='cc_relatedemailsid' alias='bb' >" +
"<filter type='and' >" +
"<condition attribute='activityid' operator='eq' value='" + entityId + "' />" +
"</filter>" +
" </link-entity>" +
"</entity>" +
"</fetch>";
objSubGrid.setFilterXml(FetchXml);
objSubGrid.refresh();
}
}
function isUCI() {
return Xrm.Internal.isUci()
}
